DAVEM TPF grant#2 report #179, #180

(this report covers two weeks)

The main two things I worked on (neither of which has been pushed yet)
were:

1) I've created a DEBUGGING-build mechanism to detect some classes of
bug where pp functions fail to extend the stack before pushing return
values. Basically the runops loop sets a high water mark variable before
calling the pp function; EXTEND() and similar update that mark, and on
return from the pp function, we check whether PL_stack_sp is > the mark
and panic if so. This has allowed me to detect and fix several such bugs
in core.

2) I've been adding a proper test suite for Porting/bench.pl, and fixing
the utility up based on the test results. For example at some point the
--bisect option broke, but this was never noticed due to no testing.

Other than that, I fixed a few bug, and fixed 32-bit builds which got
broken by utf8 values no longer being allowed to be > IV_MAX.

2017/06/05
     0:40 process p5p mailbox
     1:51 RT #131260 sprintf implementation
     4:21 apply accumulated post-5.26 fixes

2017/06/06
     0:40 process p5p mailbox

2017/06/07
     0:45 process p5p mailbox
     1:04 add better tests for Porting/bench.pl

2017/06/08
     0:13 process p5p mailbox
     1:29 add better tests for Porting/bench.pl

2017/06/09
     2:59 add better tests for Porting/bench.pl

2017/06/10
     0:26 process p5p mailbox
     2:54 add better tests for Porting/bench.pl
     0:30 RT #131555 heap-buffer-overflow

# ----

2017/06/12
     0:07 RT #131555 heap-buffer-overflow
     0:04 process p5p mailbox
     4:29 fix 32-bit builds

2017/06/13
     6:03 fix stack extend overruns

2017/06/14
     0:36 process p5p mailbox
     2:13 fix stack extend overruns

2017/06/15
     6:01 fix stack extend overruns

2017/06/16
     0:23 process p5p mailbox
     1:57 RT #131575 s// on utf8 string occasionally crashes
     0:51 RT #131577 heap-use-after-free (READ of size 1) in S_reghop4()
     1:04 update perldelta

2017/06/17
     0:02 process p5p mailbox
     7:10 add better tests for Porting/bench.pl

2017/06/18
     0:32 add better tests for Porting/bench.pl


SUMMARY:

      1:51 RT #131260 sprintf implementation
      0:37 RT #131555 heap-buffer-overflow
      1:57 RT #131575 s// on utf8 string occasionally crashes
      0:51 RT #131577 heap-use-after-free (READ of size 1) in S_reghop4()
     16:08 add better tests for Porting/bench.pl
      4:21 apply accumulated post-5.26 fixes
      4:29 fix 32-bit builds
     14:17 fix stack extend overruns
      3:49 process p5p mailbox
      1:04 update perldelta
    ------
     49:24 TOTAL (HH::MM)

-- 
Please note that ash-trays are provided for the use of smokers,
whereas the floor is provided for the use of all patrons.
    -- Bill Royston

• DAVEM TPF grant#2 report #179, #180 by Dave Mitchell